Hydraulically actuated log splitters are known, and are normally provided with a ram extended under a hydraulically generated force to drive a log into a splitting wedge. After the log is split, the ram is retracted utilizing hydraulic force acting in the opposite direction. Typically, if the ram should be obstructed during retraction, hydraulic pressure builds up, and the force exerted to retract the ram increases. This presents a safety concern if a portion of the operator's body were to be accidentally engaged by the ram during retraction.
For the safety of the operator, it is known to utilize a device which senses the pressure developed during ram retraction. The device diverts hydraulic fluid from the ram if a pressure buildup is sensed during retraction, for example by repositioning the control valve to a neutral position. Such a device is not passively safe; it requires a positive action of the device to perform the safety function.